Fix Bug PR

Contract

Prereqs:

• Run inside the target git repo.
• git and gh available on PATH, and gh auth status succeeds.
• python3 available on PATH (helper scripts parse/patch PR Markdown deterministically).
• Start from a clean working tree (avoid staging unrelated local changes).

Inputs:

• Optional PR number to operate on; otherwise resolve an open bug-type PR automatically.
• Optional label filters to narrow candidate PRs (defaults: bug, type: bug).

Outputs: